Flip-Chip Quantum Circuit With Bump Bonding

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Solution Overview

Problem

The manufacturing process of quantum computing circuits often compromises on materials and process steps due to incompatibilities between qubits and other circuit elements, leading to suboptimal performance and coherence time loss due to unwanted interactions and contamination.

Innovation Solution

A flip-chip approach where qubits and other quantum circuit elements are manufactured on separate chips using different materials and processes, then stacked together with conductive or non-conductive bonding for optimized signal routing and operation, allowing for separate optimization of each component without adverse effects.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If qubits and other circuit elements are manufactured on the same chip using the same materials and processes, then device complexity is reduced, but manufacturing precision and performance optimization deteriorate due to incompatible materials and processes

Engineering Contradiction:
Improvechip integrationVSAvoidqubit quality
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The quantum computing circuit is divided into multiple separate chips: a first chip containing qubits and a second chip containing other quantum circuit elements. This segmentation allows each chip to be manufactured with materials and processes optimized for its specific requirements, resolving the contradiction between integration and manufacturing precision.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A bump bonding structure serves as an intermediary connection between the first chip and second chip. This mediator enables electrical and mechanical connection while allowing independent optimization of each chip's manufacturing process, thus maintaining both device integration and manufacturing precision.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If materials optimized for qubit manufacturing are used, then qubit quality improves, but other circuit elements cannot be manufactured due to material incompatibility

Engineering Contradiction:
Improvequbit qualityVSAvoidcircuit element fabrication
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

By separating qubits and other circuit elements onto different chips, the patent enables each chip to use materials optimized for its specific components. The first chip can use materials ideal for qubits while the second chip uses materials suitable for other circuit elements, resolving the material incompatibility issue.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Each chip is manufactured with locally optimized materials and processes tailored to its specific circuit elements. This local quality approach allows qubit chip to have high-quality superconducting materials while other circuit element chip can use different materials, eliminating the need for compromise.

Inventive Principle:
Principle #3Local quality

3Device complexity

If all circuit elements are integrated on a single chip, then device complexity is reduced, but unwanted interactions increase causing coherence time loss

Engineering Contradiction:
Improvecircuit integrationVSAvoidcoherence time
Core Design Contradiction:
Device complexityVSLoss of energy

Solution Approach 1:

The patent physically separates qubits from other circuit elements by placing them on different chips connected via bump bonding. This spatial segmentation reduces unwanted electromagnetic interactions and energy dissipation between qubits and other elements, thereby preserving coherence time while maintaining functional integration.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent extracts qubits from the common chip environment and places them on a separate first chip. This extraction removes qubits from sources of unwanted interactions present on a fully integrated chip, reducing energy loss and coherence time degradation while maintaining necessary circuit functionality.

Inventive Principle:
Principle #2Taking out (Extraction)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This method enables the optimization of materials and processes for each component, reducing contamination and coherence time loss, thereby enhancing the overall performance of quantum computing circuits.

Implementation Method 1

conductive or non-conductive bonding for optimized signal routing and operation

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentEP3937093B1Quantum computing circuit comprising a plurality of chips and method for manufacturing the same
Publication Date: 2024.09.04 IQM FINLAND OY
  • EP3937093B1 patent drawingFigure 1
  • EP3937093B1 patent drawingFigure 2
  • EP3937093B1 patent drawingFigure 3~5

AI summary

A quantum computing circuit comprises a first chip, with at least one qubit thereon, and a second chip, with at least other quantum circuit element than qubit thereon. Said first chip and said second chip are stacked together in a flip-chip configuration and attached to each other with bump bonding that comprises bonding bumps.